Great quote silverwater! I will keep it and spread it :)
I do think it's important to have different mind sets to different topics... And I also think everything in jazz is deeply personal! Some people hate shredding and just learn by preacticing with ither people all the time. Others love to shred... Some practice deep others practice lightly and also get great results. Everyone has to know what works best for themselves... This also true to "what to practice" - different people need to practice different things in different ways. It is personal...
Some topics to me require deep concentration - ear training exercises and transcribing mainly. Learning a new song and doing exercises on a new song (scales, arpeggios, etc...) is way more relaxed. And stuff like licks or scale patterns I can even do watching TV because it forces me to practice them without thinking which is good imo... The "automatic pilot" thing can be good for this stuff.
I stopped having the "what to practice" issue when I had classes with a guy here in Lisbon that is by far the best jazz teacher I have ever seen. I have stuff to practice for the rest of my life... Some years ago I would be practicing ALL THE TIME and be really obsessive! It was an important period but I learned to relax and enjoy much more in the last year. Sometimes I have to force myself to practice but if I am not in the mood I just have fun with the guitar - improvise and compose. But if I stay too long without practicing I always put me back on track because it's really important.
Above all I would say the gigging mindset is much more important than the praticing mindset. Some people like to practice really deep but to me sometimes it feels too "heavy". Having fun and being relaxed at practicing is also important specially if you do it all the time. But total focus on the gig is the real deal and I had to work a lot on that...
PS - If you don't know what to practice just tape yourself improvising with a play-along. You will find stuff to practice right way... Or transcribe a solo, you can't go wrong with that imo. Oh and I rather practie three topics for two hours each than six topics for one hour each...